USPSTF: Screening Adults Ages 50-75 for CRC Reduces Mortality Risk

Colorectal cancer is the second leading cause of death from cancer in the United States, with the majority of cases occurring in adults 50 or older. Previous research has shown that screening for the disease has proven beneficial for this group.

"Colorectal cancer screening is a very effective, but underused, health promotion strategy in the United States," said task force member Douglas Owens, M.D., M.S., in a news release.(www.uspreventiveservicestaskforce.org) "The evidence is clear that adults ages 50 to 75 years will substantially benefit from getting screened, but about one-third of these people have never done so."

For adults ages 76-85, the task force recommends screening on an individualized basis depending on the patient's health and previous screening history -- a "C" recommendation. In this age group, patients most likely to benefit from screening are those who

have never been screened before,

are healthy enough to undergo treatment if cancer is found and

have no comorbid conditions that would significantly limit life expectancy.

Highlights

For adults ages 76-85, the task force recommends screening on an individualized basis depending on the patient's health and previous screening history.

Both draft recommendations apply to asymptomatic adults ages 50 and older at average risk for colorectal cancer.

"Colorectal cancer screening works," said USPSTF Chair Albert Siu, M.D., M.S.P.H., in the release. "We have clear evidence that it reduces the risk of dying from the disease."

Both recommendations apply to asymptomatic adults ages 50 and older at average risk for colorectal cancer -- that is, they have no family history of genetic disorders linked to a high risk of colorectal cancer (e.g., Lynch syndrome or familial adenomatous polyposis) and no personal history of inflammatory bowel disease, noncancerous growths that could lead to colorectal cancer or previous colorectal cancer.

The AAFP offered similar recommendations in 2008, as well as an additional recommendation against screening for colorectal cancer in adults older than 85.

Acknowledging that the risk-benefit profiles of various available screening methods vary, the task force discussed the pros and cons of a number of protocols, such as colonoscopy screening every 10 years, annual fecal immunochemical testing (FIT) and annual high-sensitivity guaiac-based fecal occult blood testing (gFOBT).

In its 2008 recommendation, the task force discussed screening with flexible sigmoidoscopy every five years combined with either FIT or gFOBT every three years; the current draft recommendation specifically discusses screening with flexible sigmoidoscopy every 10 years combined with annual FIT.

These changes stem from updates in the specific strategies and estimates of test performance in the most recent Cancer Intervention and Surveillance Modeling Network (CISNET) analysis.

Evidence Review

The USPSTF commissioned a systematic evidence review to update its 2008 screening recommendations that specifically examined

the effectiveness or comparative effectiveness of colonoscopy, flexible sigmoidoscopy, CT colonography, gFOBT, FIT, multi-targeted stool DNA testing and methylated Septin 9 DNA testing -- either alone or in combination -- in reducing incidence of and mortality from colorectal cancer, as well as all-cause mortality;

the harms of these screening tests; and

test performance characteristics (i.e., sensitivity and specificity) in detecting adenomatous polyps and/or advanced adenomas based on size, as well as colorectal cancer.

Unlike the 2008 evidence review, the current review expanded its search to include observational evidence about the benefits of screening tests when trial evidence doesn't exist and comparative effectiveness studies of screening tests on cancer incidence and mortality.

In addition, the USPSTF commissioned a report from the CISNET Colorectal Cancer Working Group to provide information from comparative modeling on best age ranges and intervals for screening.